too much -> allergic?

tonight, i was talking to a boy...

m: david, eat some apple
d: i ate a piece already
m: have some more
d: no.. i think i m allergic to apple
m: why? did your mom tell u that?
d: no... i think if i eat too much, i'll be allergic to it
m: did u eat a lot?
d: yes. when my mom asked me what fruit do i want, i had an apple. n i also ate some at grandma's.
m: hey... if u've eaten that many and u r still fine, then u r not allergic to it!!!

then he walked away...
i don't think he'll get apple poison like snow white....